Disaster recovery system with cascaded resynchronization
First Claim
1. A disaster recovery system with sequenced cascaded resynchronization comprising:
- a plurality of data centers, the individual data centers comprising a communication interface, a data storage, and a controller;
a distributed control system distributed and executable in the controllers of the plurality of data centers, and capable of coordinating operations via the communication interfaces of the plurality of data centers to resynchronize a plurality of communication links between data center pairs of the plurality of data centers, the communication links including at least one synchronous link and at least one asynchronous link;
a synchronous disaster recovery link that feeds an asynchronous disaster recovery link in a cascaded disaster recovery configuration; and
a control process executable on the distributed control system that responds to suspension of the synchronous disaster recovery link by suspending the asynchronous disaster recovery link prior to resynchronizing the synchronous disaster recovery link.
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Accused Products
Abstract
A disaster recovery system with sequenced cascaded resynchronization comprises a plurality of data centers and a distributed control system. The individual data centers comprise a communication interface, a data storage, and a controller. The distributed control system is distributed and executable in the controllers of the plurality of data centers, and is capable of coordinating operations via the communication interfaces of the plurality of data centers to resynchronize a plurality of communication links between data center pairs of the plurality of data centers. The communication links including at least one synchronous link and at least one asynchronous link.
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Citations
35 Claims
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1. A disaster recovery system with sequenced cascaded resynchronization comprising:
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a plurality of data centers, the individual data centers comprising a communication interface, a data storage, and a controller; a distributed control system distributed and executable in the controllers of the plurality of data centers, and capable of coordinating operations via the communication interfaces of the plurality of data centers to resynchronize a plurality of communication links between data center pairs of the plurality of data centers, the communication links including at least one synchronous link and at least one asynchronous link; a synchronous disaster recovery link that feeds an asynchronous disaster recovery link in a cascaded disaster recovery configuration; and a control process executable on the distributed control system that responds to suspension of the synchronous disaster recovery link by suspending the asynchronous disaster recovery link prior to resynchronizing the synchronous disaster recovery link.
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2. A disaster recovery system with sequenced cascaded resynchronization comprising:
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a plurality of data centers, the individual data centers comprising a communication interface, a data storage, and a controller, the plurality of data centers further comprising; a first data center; a second data center coupled to the first data center by a synchronous communication link; and a third data center coupled to the second data center by an asynchronous communication link, the third data center comprising a first data storage, a second data storage, and a copy controller capable of controlling the second data storage to store a copy of information stored in the first data storage; a distributed control system distributed and executable in the controllers of the plurality of data centers, and capable of coordinating operations via the communication interfaces of the plurality of data centers to resynchronize a plurality of communication links between data center pairs of the plurality of data centers, the communication links including at least one synchronous link and at least one asynchronous link; a synchronous disaster recovery link between the first data center and the second data center that feeds an asynchronous disaster recovery link between the second data center and the third data center in a cascaded disaster recovery configuration; and a control process executable on the distributed control system that responds to suspension of the synchronous disaster recovery link by suspending the asynchronous disaster recovery link prior to resynchronizing the synchronous disaster recovery link so that data in the third data center is not rendered corrupt and/or unusable for disaster recovery if data is lost in the first and second data centers.
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3. A disaster recovery system with sequenced cascaded resynchronization comprising:
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a plurality of data centers, the individual data centers comprising a communication interface, a data storage, and a controller, the plurality of data centers further comprising; a first data center; a second data center coupled to the first data center by a synchronous communication link; and a third data center coupled to the second data center by an asynchronous communication link, the third data center comprising a first data storage, a second data storage, and a copy controller capable of controlling the second data storage to store a copy of information stored in the first data storage; a distributed control system distributed and executable in the controllers of the plurality of data centers, and capable of coordinating operations via the communication interfaces of the plurality of data centers to resynchronize a plurality of communication links between data center pairs of the plurality of data centers, the communication links including at least one synchronous link and at least one asynchronous link; and a control process executable in the distributed control system that responds to suspension of the synchronous communication link by disconnecting the third data center second data storage information from the first data storage information prior to resynchronizing the synchronous and asynchronous communication links. - View Dependent Claims (10)
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4. A disaster recovery system with sequenced cascaded resynchronization comprising:
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a plurality of data centers, the individual data centers comprising a communication interface, a data storage, and a controller, the plurality of data centers further comprising; a first data center; a second data center coupled to the first data center by a synchronous communication link; and a third data center coupled to the second data center by an asynchronous communication link, the third data center comprising a first data storage, a second data storage, and a copy controller capable of controlling the second data storage to store a copy of information stored in the first data storage; a distributed control system distributed and executable in the controllers of the plurality of data centers, and capable of coordinating operations via the communication interfaces of the plurality of data centers to resynchronize a plurality of communication links between data center pairs of the plurality of data centers, the communication links including at least one synchronous link and at least one asynchronous link; and a control process executable in the distributed control system that responds to a failure condition comprising; a first subprocess that suspends the asynchronous link; a second subprocess activated after the first subprocess that disconnects the third data center second data storage information from the first data storage information; a third subprocess activated after the second subprocess that resynchronizes the synchronous link between the first data center and the second data center; a fourth subprocess activated after the third subprocess that resynchronizes the asynchronous link between the second data center and the third data center; and a fifth subprocess activated after the fourth subprocess that reconnects the third data center second data storage information from the first data storage information. - View Dependent Claims (5, 6, 7, 8, 9)
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11. A disaster recovery system with sequenced cascaded resynchronization comprising:
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at least three data centers in a configuration including; a first data center; a second data center linked to the first data center by a communication link; and a third data center linked to the first data center and the second data center by communication links, information being multicast at least from the first data center to the second and third data centers; and a distributed control system distributed and executable in the at least three data centers, the distributed control system being configured to respond to failure of the link between the first and second data centers by transferring a bitmap representing a differential copy of information from the first data center to the second data center via the third data center. - View Dependent Claims (12, 13, 15, 16)
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14. A disaster recovery system with sequenced cascaded resynchronization comprising:
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at least three data centers in a configuration including; a first data center; a second data center linked to the first data center by a communication link; and a third data center linked to the first data center and the second data center by communication links, information being multicast at least from the first data center to the second and third data centers; a distributed control system distributed and executable in the at least three data centers, the distributed control system being configured to respond to failure of the link between the first and second data centers by transferring a bitmap representing a differential copy of information from the first data center to the second data center via the third data center; and at least one memory associated with the at least three data centers, the at least one memory being capable of storing an asynchronous sidefile bitmap, the distributed control system being responsive to the link failure between the first and second data centers by transferring an asynchronous sidefile bitmap from the first data center to the second data center via the third data center, the second data center being capable of using the asynchronous sidefile bitmap to update information in the third data center in a differential update.
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17. A method of responding to failure of a link in a daisy-chained multiple-site disaster recovery configuration including a first data center, a second data center synchronously linked to the first data center, and a third data center asynchronously linked to the second data center, the third data center having an internal copy linkage, the method comprising:
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distributing control operations among the first, second, and third data centers; coordinating control among the first, second, and third data centers; suspending the asynchronous linkage between the second and third data centers; disconnecting the internal copy linkage of the third data center when the asynchronous linkage is suspended; resynchronizing the synchronous linkage between the first and second data centers following disconnection of the internal copy linkage; resynchronizing the asynchronous linkage between the second and third data centers following resynchronization of the synchronous linkage; and reconnecting the internal copy linkage when the synchronous and asynchronous linkages are resynchronized. - View Dependent Claims (18, 19, 20)
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21. A method of sequenced cascaded resynchronization comprising:
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communicating data and control information among at least three data centers; multicasting from a first data center to second and third data centers; distributing control operations among the first, second, and third data centers; and responding to failure of the link between the first and second data centers by transferring a differential copy of information from the second data center to the third data center, based on a differential bitmap copied from the first data center to the second data center via the third data center. - View Dependent Claims (22, 23, 24, 25, 26, 27)
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28. A disaster recovery system with sequenced cascaded resynchronization comprising:
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at least four disk arrays in a configuration including; a first disk array including a remote mirror primary volume storage; a second disk array including a remote mirror secondary volume and local mirror primary volume storage linked to the remote mirror primary volume storage by a first communication link, the second disk array also including a local mirror secondary volume and remote mirror primary volume storage internally mirror linked to a remote mirror secondary volume and local mirror primary volume storage by a second communication link; and a third disk array including a remote mirror secondary volume storage linked to the second disk array local mirror secondary volume and remote mirror primary volume storage by a third communication link; and a fourth disk array linked to the remote mirror secondary volume storage by a fourth communication link; a distributed control system distributed and executable in the at least four disk arrays, the distributed control system coordinating timing of data mirroring to promote consistency of the mirrored copies; the first through fourth communication links comprising a synchronous disaster recovery link that feeds an asynchronous disaster recovery link in a cascaded disaster recovery configuration; and a control process executable on the distributed control system that responds to suspension of the synchronous disaster recovery link by suspending the asynchronous disaster recovery link prior to resynchronizing the synchronous disaster recovery link. - View Dependent Claims (29, 30, 31, 32)
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33. An article of manufacture comprising:
a controller usable medium having a computable readable program code embodied therein for responding to failure of a link in a daisy-chained multiple-site disaster recovery configuration including a first data center, a second data center synchronously linked to the first data center, and a third data center asynchronously linked to the second data center, the third data center having an internal copy linkage, the computable readable program code further comprising; a code capable of causing the controller to distribute control operations among the first, second, and third data centers; a code capable of causing the controller to coordinate control among the first, second, and third data centers; a code capable of causing the controller to suspend the asynchronous linkage between the second and third data centers; a code capable of causing the controller to disconnect the internal copy linkage of the third data center when the asynchronous linkage is suspended; a code capable of causing the controller to resynchronize the synchronous linkage between the first and second data centers following disconnection of the internal copy linkage; a code capable of causing the controller to resynchronize the asynchronous linkage between the second and third data centers following resynchronization of the synchronous linkage; and a code capable of causing the controller to reconnect the internal copy linkage when the synchronous and asynchronous linkages are resynchronized.
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34. An article of manufacture comprising:
a controller usable medium having a computable readable program code embodied therein for sequenced cascaded resynchronization, the computable readable program code further comprising; a code capable of causing the controller to communicate data and control information among at least three data centers; a code capable of causing the controller to multicast from a first data center to second and third data centers; a code capable of causing the controller to distribute control operations among the first, second, and third data centers; and a code capable of causing the controller to respond to failure of the link between the first and second data centers by transferring a bitmap representing a differential copy of information from the first data center to the second data center via the third data center. - View Dependent Claims (35)
Specification